Device for stepless variation of machine stroke length during operation



Jan. 14, 1969 5 3,421,378

DEVICE FOR STEPLESS VARIATION OF MACHINE STROKE LENGTH DURING OPERATIONFiled Sept. 12. 1 966 Sheet of 4 INVENTOR 6457/52 1 o'xwvc ATTORNEYSJan. 14, 1969 DEVICE FOR STEPLESS VARIATION OF MACHINE STROKE LENGTHDURING OPERATION Filed Sept. 12. 1966 G. LCRINC Fig. 2

A T l a Fig. 3

Sheet 2 of 4 INVENTOR you-7,

ATTORNEYS Jan. 14, 1969 G. LORINC 3,421,373

DEVICE FOR STEPLESS VARIATION OF MACHINE STROKE LENGTH DURING OPERATIONFiled Sept. 12, 1966 Sheet 2 of 4 INVENTOR GA'sP/e Ldie/A/c BY Z Z IATTORNEYS G. LORINC 1 DEVICE FOR STEPLESS VARIATIONOF MACHINE STROKEJan. 14, 1969 LENGTH DURING OPERATION Filed Sept. 12. 1966 SheetINVENTOR GA'SPJR Adieu/c ATTORNEYS United States Patent 3,421,378 DEVICEFOR STEPLESS VARIATION OF MACHINE STROKE LENGTH DURING OPERATION GasparLtirinc, Budapest, Hungary, assignor to Nikex Nehezipara KulkereskedelmiVallalat, Budapest, Hun- Filed Sept. 12, 1966, Ser. No. 578,867 Claimspriority, applicaltgiim2 Hungary, Sept. 15, 1965,

U.S. Cl. 74-41 Claims Int. Cl. F1611 21/32 ABSTRACT OF THE DISCLOSUREApparatus for adjusting during operation the stroke of a piston or otherreciprocating member, from zero to a maximum, by means of a remotecontrol, especially for mortar pumps. The apparatus includes apower-driven swinging slide, driven by an electromotor which is remotelycontrolled. The slide is suitably connected to the piston.

The conventional mortar pumps are used for conveying mortar or othersimilar material, such as concrete, from the spot of mixing to the placeof use. The output required from such pumps varies in conformity withthe conditions of work. Thus, for example, a much higher output isrequired for building a new wall than in the case of mechanicalplastering or rendering.

It is, accordingly, essential to be able to vary the output of suchpumps during their operation in a continuous manner, a requirement whichcould not be satisfied in a simple manner by conventional equipments. Itis the objeet of the invention to alter the output of pumps and othermachines or implements comprising pistons in such a manner that thestroke is adjusted, and to make such alteration continuous and effectedby remote control. It is a further object of the invention to reduce thestroke to zero, so that feeding of mortar may be stopped with themachine still running.

It is a still further object of the invention to effect adjustment ofthe output by simple means, with full operational safety and without ashock effect, whereby the constituent parts of the machine are sparedand their life may be considerably lengthened.

In order to realize these aims, the machine or implement according tothe invention is built up so as to comprise on an alternating machinepart, for instance on the piston rod, a swivelling slip block and aswinging slide displaceable in relation to said slip block, connected atone extremity to the drive gear, for instance to the crank rod, and atits other extremity to a movable carriage, however it does notcommunicate directly with the carriage but by means of two insertedmembers, one of which is a fork fastened to one of the extremities ofthe swinging slide, connected tilting to the other member, i.e. to thefixed fork which is secured on the carriage and is placed within thefirst mentioned fork. In this way an engagement constituted by an outerfixed and an inner tilting fork will come about. The inside fork ispreferably fitted on cantilever pins, secured in the outside fork. Themovable carriage can be actuated in both senses of rotation, it ispreferably connected to a remote-controlled electromotor and limitswitches are provided at the two end positions of the carriage.

The invention is illustrated more particularly by means of the attacheddrawings of two of its embodiments shown by way of example.

FIGURES 1 to 3 illustrate a device set to zero stroke coupled to aunilaterally working internal guide piston. FIG. 1 is a longitudinalsection of the device in the plane F-G of the piston (FIG. 2). FIGURE 2shows a cross section taken along C-D-E. FIGURE 3 is a section takenalong the line A-B.

FIG. 4 is a longitudinal section of another embodiment and FIG. 5 is across section taken along lines A-B. FIG. 6 is a section along the planeC-D.

.In the outer fork-shaped extremity of the piston 2 or another machinepart alternating in the body 1 there is arranged a slip block 3, thebilaterally extending pins of which are pivoting and supported onbearing covers 4. Longitudinally displaceable in a bore of the slipblock 3 there is arranged a swinging slide 5 on one end (on the upperend in the figure) of which an inner tilting for 6 is secured by a nut.The outer smooth extremities of cantilever pins 7, on which an innerfork 6 may pivot, penetrate in the lower bores of fork 6. The pins 7 arefastened by means of a fine thread in an outer fixed fork 8, theiroutside extremities being for-med as screw heads. The swinging slide 5is brought in swinging motion by a crank rod 11 actuated by a trunnion10, through pin 12 seated in a fork-shaped extremity of the crank rodand in the extremity of the slide 5.

On a guide built of the machine body a movable carriage 13 is located,on which the outer fixed fork 8 is secured by means of a stud 14. Incase of larger loads the fixed fork may be worked out of the same pieceas the movable carriage 13, instead of being secured by studs. Theswinging slide 5 in its swinging state can be displaced in respect tothe slip block 3 by turning a screw spindle 15. The screw spindle 15 isturned by a wedged worm wheel 16 and an associated pulley 17, the latterbeing driven in both senses of rotation by a servo motor 18 incompliance with impulses coming from remote control push buttons.

The trunnion 10, caused to rotate by a driving means drives the swingingslide 5 by means of the crank rod 11. The slide 5 is tilted about thecantilever pins 7 to and fro, with the insertion of a titlting fork 6which is connected, as represented in FIG. 1, to the upper part of theslide 5. The inner fork 6 is rotatably mounted of the outer fixed fork 8which is connected by means of a nut 14 to the support carrier 13. Itsaid carriage 13 is moved up and down, the slide 5 is displaced by meansof the fork 8, the pin 7 and the fork 6, in relation to the block 3, sothat the actual position of the carriage 13 determines the length of thestroke. The stroke is longest when the carriage is at the largestdistance from the piston, and the piston stands still, i.e. the strokeis reduced to zero, if the centre point of the pin 7 is in the virtualextension of the centre line of the piston.

The carriage can be adjusted to any desired position during operation,so that the stroke may be easily adju-sted from zero to maximum withoutthe need for cutting out the machine.

In FIGURES 4 to 6 the device is represented as conneoted to an insideand outside guided piston set to the maximum stroke length. The swingingslide consists of two parallel rods.

The piston or other alternating machine part moving in the body 1 has aninner passage and the slip block 3, turnable on a toggle 19 pressed intothe piston body 2, is installed in this passage. The toggle is securedat both extremities by inner spring retainer rings 20. In the slip block3 two slides 5 made of parallel compact or full rods interconnected atone end (the upper end in the figure) by means of the fork 6, at theother end (the lower one in the figure) by a pinned clamp 21, may freelybe displaced in the slide block 3. In the inner, tilting fork 6 theouter fixed fork 8 is arranged. The fiat ends of the cantilever pins 7are connected, preferably through self-aligning roller bearings 24, tothe fork 6.

Hence, in addition to frictionless rotation and easily realizablelubrication, also inaccuracies arising of a possible processing ormounting error can be compensated.

The outer stationary fork 8 is fastened by means of a stud 14 to thecarriage 13 moving on a guide 23. The swinging slide formed of parallelrods is set in motion by the crank rod 11 by means of the pin 12 seatedin the fork-shaped extremity of the crank rod and in the bore of thepinned clamping member 21. Displacement is effected by turning the screwspindle 15, which is turned by the wedged worm wheel 16 and theassociated pulley 17, the latter being driven in both senses of rotationby a servo motor 18 in compliance with impulses coming from the remotecontrol push buttons.

A hand-operated actuator 22, represented by dashed lines in FIGURE 4,for example a crank, permits in emergency cases to shift and to controlthe slide 5 by hand-power. This hand-operated actuator may be employedon any embodiments of the device. Likewise, any of the embodiments canbe fitted with limit switches for cutting out of the servo motor.

The advantages of the invention in relation to the known devices and itsfields of application are numerous. So it is an important advantage thatfor concrete pumps after stopping the pump for short intervals thedriving motor can be started unloaded and the motor, running at fullspeed, can be progressively loaded. The known devices do not afford thispossibility.

Applied likewise in mortar pumps, the device according to the inventionpermits to efiect high pressure grout injection in damming works,storage dams, sluice chamber heads, subway tubbings and the like. Theswinging slide, displaced from the zero stroke, forms an ever growinglever so that with the same motor, though with lessening mortar quantitytransfer, a growing mortar pressure can be achieved. So until the cavityis not filled, a large quantity of mortar can be transferred essentiallywithout pressure and when a counter pressure arises, the pressure can beincreased up to the required value by displacing the swinging slide.

The device according to the invention can also be used in machines orimplements other than mortar and conorete pumps, for instance in mining,in the chemical industry, in comminuting machines and sorters, in thebuilding industry, in conveyors and wherever stroke actuation and strokeregulation is needed.

The device may be used also in presses, for instance for chip, fibre orplastic materials, where initial low pressure must be infinitelyincreased to a higher one.

I claim:

1. Apparatus for adjusting the stroke of a reciprocating member duringoperation, comprising a slip block tiltingly disposed on thereciprocating member, driving means for the, reciprocating member, aswinging slide fixed at one end on the driving means and displaceablealong said slip block, a movable carriage, an inner fork connected tothe swinging slide, and an outer fork mounted on the carriage, saidswinging slide and movable carriage being tilta'bly interconnected bysaid forks.

2. Apparatus as claimed in claim 1, and a cantilever pin mounted in theouter fork, said inner .fork lbeing rotatable about said cantilever pin.

3. Apparatus as claimed in claim 1, said swinging slide being in theform of a rod displaceable in said slip block.

4. Apparatus as claimed in claim 1, said swinging slide consisting oftwo parallel rods clamped together at their ends, said inner forkclamping said rods together.

5. Apparatus as claimed in claim 1, and a remotely controlledelectrically dn'ven servomotor for displacing said swinging slide.

6. Apparatus as claimed in claim 5, and limit switches for automaticcutout of said servomotor, and means mounting said limit switches :foradjusting to any of a plurality of desired positions.

7. Apparatus for adjusting the stroke of a reciprocating member duringoperation, comprising drive means for the reciprocating member, a slipblock tiltingly disposed on said reciprocating member, a swinging slidefixed at one of its ends on said drive means and displaceable along saidslip block, a movable carriage tiltingly connected to the other end ofsaid swinging slide, an inner fork connected to the swinging slide, anouter fork mounted on the carriage and guided in a straight guide, thetwo forks connecting the said swinging slide to the movable carriage, acantilever pin mounted in the inner fork, the inner fork being rotatablearound said pin, said inner fork and pin and outer fork moving togetherwith said carriage, and a remotely controlled electrically drivenfixedly mounted servomotor for displacing said swinging slide.

8. Apparatus as claimed in claim 7, in Which the swinging slide has theform of a rod and is displaceable in the slip block.

9. Apparatus as claimed in claim 7, in which said swinging slideconsists of two parallel rods clamped together at their ends, said innerfork clamping the said rods.

10. Apparatus as claimed in claim 7, and limit switches for automaticout-out of said servomotor, and means mounting the limit switches foradjusting to any of a plurality of desired positions.

References Cited UNITED STATES PATENTS 764,573 8/1904- Furru 74411,058,878 4/1913 Lowndes 64l8 1,369,164 2/1921 Christopher 74-462,391,418 12/1945 Hodgson et al 74625 2,548,807 4/1951 Morgan et al.74-41 2,958,237 11/1960 Johnson 74-41 3,139,760 7/1964 Pfeifer 7444 FREDC. MATTERN, JR., Primary Examiner. W. S. RATLIFF, Assistant Examiner.

U.S. Cl. X.R. 64-18; 7446, 841

